Pellet Grill/Smoker Temperature Swings (Normal or Broken?)

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One of the key reasons pellet grills/smokers are so popular is due to their automated nature, in other words, they save you time. You’re not managing the fire. The control panel of the pellet grill/smoker is doing that for you. Every pellet grill is going to have at least some swing in its temperature above and below the set temperature. However, some have wider temperature swings than others and sometimes that temperature swing is needed to actually produce smoke. Let’s discuss what’s normal and when it might be broken.

Pellet Grill/Smoker Temperature Swings
It would be completely normal for the Traeger on the left to swing about 25 degrees around the set temperature, but the Traeger on the right to only swing about 5 degrees around the set temperature, but why is that?

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Introduction To Pellet Grill/Smoker Temperature Swings

So you may be confused by my image caption above, why would it be normal for two pellet grills from the same brand in that case Traeger to have different amounts of temperature swing!?

Well, the reason is that while both pellet grills are branded as ‘Pro Series’ models, the model on the left is a Gen 1 version and the model on the right is a Gen 2 version.

I have a separate article that goes into all the differences between the Traeger Pro Series Gen 1 vs Gen 2.

Anyway, the main difference relevant to this article is Gen 1 Pro Series is running an older generation time-based control panel where its normal to see a 25-degree temperature swing on either side of the set temperature.

Time-Based vs PID Control Panel Temperature Swings
These are both Traeger control panels. However, the left is an older time-based control panel, and the on the right is their more modern PID control panel

The Gen 2 Pro Series is fitted with what’s known as a PID control panel which uses an algorithm to constantly monitor and adjust the combustion process.

Typically PID control panels are more accurate and will reduce the temperature swing to within 5 degrees.

I say ‘typically’ because some PID controls fitted to some other brands of pellet grills are not quite as accurate, and owners should expect a wider swing of around 10 degrees.

Z Grills PID control panels and Expert Grills are two examples.

Is Your Control Panel Time-Based Or PID?

So the first step to understanding if the temperature swing on your pellet grill/smoker is ‘normal’ is to find out if its fitted with a previous generation time-cased control panel or a more modern PID control panel.

If you’re not sure the manual should state what type of control panel technology is being used and in most cases, it should actually state what ‘normal’ temperature swings you should expect.

Don’t be under the impression its just Traeger now fitting PID control panels. I have a separate article (here) discussing which brands are currently using this control panel technology.

Normal Smoke Setting Temperature Swings

Most pellet grills whether they are fitted with a previous generation time-based control panel or a more modern PID algorithm control panel have a ‘Smoke’ setting.

It’s normal on both control panel technologies to see wider temperature swings than normal.

For instance, on time-based control panel pellet grills many have the option to adjust what’s called the P-Setting.

This simply refers to a pause setting, in other words, the duration of the pause in time between the auger turning on and off feed pellets to the fire.

Pellet Grill Smoke Setting Temperature Swings
Even on a modern PID control panel, when smoke settings are used, more swing should be expected in the temperature than under normal operation

Different P-Settings are required for the best performance in summer and winter. Hence, if a less-than-ideal P-Setting is used, the pellet grill/smoker will have wider temperature swings.

My article linked above on the P-Setting goes into more detail on this topic.

Several PID control panels also have a Smoke setting, and as I discussed in the linked article when used, the temperature accuracy will be wider than 5 degrees on either side of the set temperature.

Why? Well, to produce smoke, you need inefficient combustion. You need a less ideal mixture of fuel and air.

Hence, the PID control in Smoke mode effectively dumbs itself down to produce more smoke, which at the side time results in wider temperature swings than under normal operation.

Check The Pellet Grills RTD Temperature Sensor

So after reading the above on what ‘normal’ temperature swings you should expect from a pellet grill/smoker now let’s discuss scenarios that might not be normal.

Potentially a broken component, or more likely in this case a dirty component that needs cleaning.

The RTD temperature sensor sits inside the cooking chamber of the pellet grill/smoker, and it’s what tells the control panel what the internal temperature is.

Now, in some cases, these temperature probes can fail and require replacement as I have discussed previously in my article on Traeger RTD probe replacements.

Pellet Grill RTD Temperature Probe
Some pellet grills, such as this Traeger, have the RTD probe on the left side of the cooking chamber. Some other brands place them at the back or on the right side of the cooking chamber

In many cases, the RTD probe may just need a good clean to remove excessive grease/fat, which is insulating the probe from what the true temperature inside the grill actually is.

Hence, if the probe doesn’t know the real temperature, neither does the control panel.

Most pellet grills have just one RTD probe. However, we are now seeing models such as the Traeger Timberline Gen 2 and the Oklahoma Joe’s Rider Gen 2, which feature multiple temperature sensors.

My point is, to check how many your grill has and clean them appropriately.

The Quality Of Your Pellets Matters A Lot

Ok, let’s say you understand your pellet grill control panel characteristics and what normal temperature swings you should expect from it.

Let’s also say you have checked, cleaned or even replaced the RTD temperature probe, as discussed above.

If you are still experiencing temperature swings beyond what you should normally expect, you then have to look at the quality of your pellets.

Its important to note, that I’m not talking about blended vs single species pellets or 100% charcoal pellets vs blended pellets, I’m talking about density and durability.

How To Test Wood Pellet Quality
Here is how to quickly test the quality of your BBQ pellets

If the pellets have not been protected from moisture, then pellets can go bad, by this, I mean they have a reduced density and durability.

What that means is in the hopper and travelling through the auger, they will be broken up into smaller pieces. The result is reduced combustion performance and, as a result, wider temperature swings.

It’s also important that bags of pellets are handled with care, and sometimes that is not the case. As a result, when you open the bag, there can be lots of fines/dust in the bottom of the bag.

Therefore, I always recommend sieving pellets before you load them into the hopper.

My Final Thoughts On Pellet Grill/Smoker Temperature Swings…

From reading the above, I hope you now have a better understanding of what you should expect in terms of ‘normal’ temperature swings on a pellet grill/smoker.

However, also what you should look into if you think you are experiencing wider than normal temperature swings.

Cleaning the RTD temperature probe and making sure you are using high-quality pellets (good density and low dust) can make a big difference in many cases. However, there is one final factor to look into.

As PID control panels run algorithm software to maintain temperature, sometimes this software/firmware does need an update.

There have been a couple of times where this has been the case in recent years (Pit Boss Gen 2 Pro Series).

That’s it! I hope you found the above informative/useful. As always, please check out my Wood Pellet Grill/Smoker Guide to learn more. 🙂

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